public class 螺旋打印 {
public List<Integer> spiralOrder(int[][] matrix) {
int tR = 0;
int tC = 0;
int dR = matrix.length - 1;
int dC = matrix[0].length - 1;
List<Integer> list = new ArrayList<>();
while (tR <= dR && tC <= dC) {
printList(matrix, list, tR++, tC++, dR--, dC--);
}
return list;
}
private void printList(int[][] matrix, List<Integer> list, int tR, int tC, int dR, int dC) {
if (tR == dR) {//只有一行了
for (int i = tC; i <= dC; i++) {
list.add(matrix[tR][i]);
}
} else if (tC == dC) {//只有一列了
for (int i = tR; i <= dR; i++) {
list.add(matrix[i][tC]);
}
} else {//一般情况
int curR = tR;
int curC = tC;
while (curC < dC) {
list.add(matrix[tR][curC++]);
}
while (curR < dR) {
list.add(matrix[curR++][dC]);
}
while (curC > tC) {
list.add(matrix[dR][curC--]);
}
while (curR > tR) {
list.add(matrix[curR--][tC]);
}
}
}
public static void main(String[] args) {
int[][] nums = {
{1,2,3,4},
{5,6,7,8},
{9,10,11,12}
};
System.out.println(new 螺旋打印().spiralOrder(nums));
}
} 
